[PATCH net] ibmvnic: Do not process reset during or after device removal

[PATCH net] ibmvnic: Do not process reset during or after device removal

[Thomas Falcon]

Currently, the ibmvnic driver will not schedule device resets
if the device is being removed, but does not check the device
state before the reset is actually processed. This leads to a race
where a reset is scheduled with a valid device state but is
processed after the driver has been removed, resulting in an oops.

Fix this by checking the device state before processing a queued
reset event.

Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index cebd20f..fa4bb94 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1983,6 +1983,10 @@ static void __ibmvnic_reset(struct work_struct *work)
 
 	rwi = get_next_rwi(adapter);
 	while (rwi) {
+		if (adapter->state == VNIC_REMOVING ||
+		    adapter->state == VNIC_REMOVED)
+			goto out;
+
 		if (adapter->force_reset_recovery) {
 			adapter->force_reset_recovery = false;
 			rc = do_hard_reset(adapter, rwi, reset_state);
@@ -2007,7 +2011,7 @@ static void __ibmvnic_reset(struct work_struct *work)
 		netdev_dbg(adapter->netdev, "Reset failed\n");
 		free_all_rwi(adapter);
 	}
-
+out:
 	adapter->resetting = false;
 	if (we_lock_rtnl)
 		rtnl_unlock();
-- 
1.8.3.1

Re: [PATCH net] ibmvnic: Do not process reset during or after device removal

[David Miller]

From: Thomas Falcon <tlfalcon@linux.ibm.com>
Date: Tue, 27 Aug 2019 11:10:04 -0500

> Currently, the ibmvnic driver will not schedule device resets
> if the device is being removed, but does not check the device
> state before the reset is actually processed. This leads to a race
> where a reset is scheduled with a valid device state but is
> processed after the driver has been removed, resulting in an oops.
> 
> Fix this by checking the device state before processing a queued
> reset event.
> 
> Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
> Tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
> Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>

Applied.